Process of making metallic sheets by electroplating



Jan. 8, 1929. l 1959A ce. vUNGaL-ui xuomas'sA or umm; asume, smears avsmcmormme Filed sept.' 19, 19g? o 'A :Ivi/agirait.`

Patented Jen. s, 1929.

l 'UNITED VsTArEs 1,698,486 'ENT` OFFICE.

PAT

GIBSON 'YU'NGBLUT, DAYTON, KENTUCKY, ASISIGNOR T0 THE-BICHARDS-ON COIL-yIEANY, OF LOCKLAND, OHIO, A CORPORATION OF O HIO.

Appneati'en mea september 1e, 1927. serie1Ne.22o,35e.

My invention relates to the production of metallic sheets or otherarticles'by electrodeposition of metal upon a base platel from which thedeposited metal is subsequently freed by an electrolytic differentialsolution atl all.

stripping step. In a. separate application tiled by the presentapplicant and John R. Cain, such a process is described, in which forexample, a double thickness plate of copper 4is placed in anelectrolyticcell and has deposited upon it a double .thicknessplate ofiron. This composite plate'is then rolled so as to double its length andhalve its thickness, is cut into two parts, .and both parts are 4placedin a suitable. stripping cell. .The 4action of this cell lwhen ironsheets are desired as a inished product will be controlled so that thecopper will be entirely dissolved from one of the iron sheets and builtup upon the copper face of the corresponding copper-iron sheet. e i

The bare iron sheet is then, so far as this process is concerned, a;finished product.A

Thecopper-iron plate, consisting of a double thickness of copper and asingle. thickness of iron,' is then returned' to the iron plating bath,and the process is repeated cyclieally.

It is the object of this invention to permit the production of sheets ofelectrolytic metal upon base plates from which theyare subsequentlyremoved without having been rolled My processes although useful in theproduction of other kinds of particularly adapted to the making oi eX-tremely thin metallic bodies, `itoils of iron or iron alloys fortransformer use, and especially foils of the precious metals.'

It is another object 'of my invention to pro` vide in such a processmeans continuously to lregenerate the base plates.

Itis another object of my invention to provide means wherebyy the baseplate Asurface will always be clean, bright and rolled when .it'is`plated upon.v My process does away with the thickening of anelectrodeposit previously formed and previously worked in connectionwith a base plate, so that my electrolytically deposited sheets willalways be formed with one face Jfreshly deposited against'aireshlypolished surface.

' It is another object of my invention to do away with' any necessaryrelationship between'the hardening and thickening of the base plate andthe hardening and thickening of the electrodeposited sheet thereon, soas to sheets, .is thusv permit the depositing of extremely thin foilsupon a base'plate 'so thick as to be conveniently handled, or thedepositing' of thick sheets upon base plate so thin as to minimize thetime and current consumption of the stripping process.

Itis another object of my invention to form an electrodeposited nishedproduct which, because it need not be rolled, need not-be annealed orotherwise treated. Metals and particularly iron when electrodepositedhave certain .crystalline structures and electric and magneticproperties which are altered by-subsequent treatments and may 'notthereafter be restored.

It is another object of my invention to provide, in a system involvingthe'regeneration 'of base plates, means of compensating'for the loss ofmetal in trimming after the rolling operation. y l

Other objects will be apparent to those skilledin the art upon readingthese specifications. f

I accomplish my objects by that' certain series ot' steps which willhereinafterbe specifically pointed out in atypical example and thenovelty inherent in which will be set forth in the claims that follow.

In the drawings The ligure is a diagram in which the sheets and baseplates are represented in side elevation and 4which shows the variousnamed steps of my process.

Since my inventi combination of steps, no attempt is made in thedrawings to illustrate other than diagrammaticallyvarious rolling andelectrolytic processes which are within the knowledge of one skilled inthe art to perform.

My process involves the use of two base plates, or series of'baseplates, of one metal 'M, which I have indicated in the figure as on`consists vin the novel- M-l and M-2. The finished sheets which I dpsireare of a diierent metal indicated as T.

The process consists, briey, in placing a base plate M-l in anelectrolytic bath A in which is an'electrolyte B comprising a solutionof the salt of the metal N. A suitable anode' C is placed in the celland through the action of a source of electrical energy, not shown,connected both to the anode and the cathode of the electrolytic couple,an electrodeposit of the metal N is formed upon the cathodic base plateM--1. The product otA this operation, designated as M-1--N, istransferred to an electrolytic stripping cell D in which the base plateM-l is dissolved, leaving as an end product the desired metallic plateN.

Inthe electrolytic stripping cell D the electrolyte isa solution of asalt of a metal M which will attack vunder electrolytic condi- `AfterWashing, this cathode is passed one or more times through suitable rollswith inter-` vening annealing operations. if necessary, so

thatlits thickness is halved and its length doubled', whereupon it iscut into tivo parts.

It will be -obvious that the result of this process is to regeneratethc' plates M -l and lM-2. M-l is transferred back to the electrolyticcell .A and M-Q'to the eleetrolytic stripping cell D.

It will be seen that I have formed my finished product N by the simpleoperation of forming it electrolytically Aupon a cathode blank and thenfreeing it from said blank by an electrolyt-ic differential solutionstep, It

has not been rolled, annealed or 'otherwise treated, and the advantagesof'this process in forming foils from metallic deposits so thin thatthey cannot be Worked or rolled Will be immediately apparent.

In the commercial operation of my process M l and M-Q will representseries of blanksrather than single ones, andthe number of couples in theseries A and D, itthe couples are connected in parallel, may beincreased as much as desired, or the number of cells 1nci'cascd it' thecouples are connected in series,

The' rolling opera-tion will necessitate trim# innig ott the edges and1t will be secu that since the blanks M-l and M-2 are alreadyti-iiiiini\d and ot proper thickness, some-means for the trim, or 1nother Words, for increasing the amountr niiistbe taken for compensa tinof metal inthe composite M-1'-l\I 2:f Anl other Way of stating this isto say that the composite 'M`l-M-2 before rolling must contain a Weightofy metal equivalent to M-1 plus M-2 plus the average or necessary trim,it1 the thickness oi the platesM-l and M-2 is notcontinuously todiminish.

I compensate for this trim by placing in the stripping cell asupplementary anode M-3 connected to a source of current (which willalso be connected to the cathode M-?) of such value as to deposit upon Ma Weight of metal equivalent to the calculated neces- .stripping of M-lfrom the iii `,manu,f'actureI n process outlined'ginfthelap lic-ation ofJohn sary trim during the time required by' the ished plate N. Thus thecathode taken from the stripping cell at the end of the strippingoperation will consist of M-l plus .hl-2 plus some metal from thesupplementary anode. If the w eight of metal in M-l and M-2 is indicatedas X and the Weight of the calculated trim as Y, the weight of thecomposite cathode from the stripping bath may be expressed as 2X`plus Y.After rolling, trimming and cutting, therefore, M-l and M-Q would beregenerated and there Would be left over an amount of trim equivalent tothe weight of -metal deposited from the supplementary anode. -In thecommercial operation this trim will be renielted and cast intosupplementary anodes M---3, or may be used in a basket or some otherdevice which Will make remelting unnecessary.

I will now describe the operation of my invention in a typical example,that is to say, the formation of very thin iron sheets on a base plateof copper.. I start with a base plate of copper of any desiredthickness,

which may conveniently' be .02. The thicklness Will be controlled by theoperator in acp convenience in handling thesize of sheet to be produced,and it will be seen that in a process for the production of cordanceWith his .metallic bodies of comparative thinness, the

size and shape of thecathode blank or plate Will determine the size andshape of the finished electrodeposited article. Thus in the manufactureof thin electrolytic iron for electrical purposes, the cathode blank Mmay be stamped or cutinto a.y certain configuration as, for example, thecore ofy a transformer or armature. Resort maybe hadV to shielding orother devices for preventing the'electrodeposit of iron around'the edgesor upon the reverse side of the cathode blank, or the cathode blank maybe treated with an insulating compound Vover the portions ii pon whichno deposit is desired. In thisman- ,neiytwo or more finished articlesmay be foi-ined. uponone cathode blank. This is of particular advantage)if'here numerous small articles are desired. IY prefer'fto employmiiiieii A for ai@ elctrolytic iron the R. Cain. filedv harcli 8, 192Serial No. 173,- 794, 'and thel anode described in John R. Caiifsapplication filed March 8, 1927, Serial No. 173,793.

Electrical vconnection is made With a direct current low voltage dynamoor vvother source of electrical energy and iron is deposited upon thedesired portions ot the cathode blank to the thickness required in thefinished product. A

I then remove the cathode blank M-l with its adhering deposit ordeposits of iron and place it in a separate electrolytic cell r-ent, Icarry ona dili'erential, stripping of the copper from the compositeblank M1-N, placing in my cell supplementary yanodes of cast copper M-Bconnected to a supplementary source of current of such value as Willdepositl upon the cathode 'blank' a Weight of metal calculated tocompensate fort-he trim. This will obviously vary withthe size of thesheet to be produced and the character of the rolling operation.

In cases where I ani producing` more than one'iron article upon aisingle copper cathode blank, I take careto'see that each article lisconnected individually to the source olelectrical energy. The reason forthis is that as stripping action progresses, the copper plate may bedissolved unequally and ifa part of it were detached and fell to thebot.-

tom of the tank so as to break its electrical connection with thepositive 'side of the current source, stripping action on this piecewould stop. 4This may be takencare of b-y supplementary connections orby leaving,

through the insulation applied to the face of the plate M-ll, pathspermitting the .deposition of ironand leading to the point at whichcurrent connection Will be made.

Copper hardens rapidly upon Working and I have found it, therefore,advantageous to 'anneal the copper cathode indicated in Figure 1` asM-l-M-2' after one or more passes through the cold rolls. I prefer toA,use for this annealing a bath of hydrocarbon oil heated to-around400C." centigrade such as is described in the application of John R.

' Cain filed June 17, 1926, Serial No. 116,723. 1 This annealingoperation docs not result in the formation of any scale, or oxide, andafter annealing,'if the piece' is to be returned tothe rolls, -it isonly necessary to pass it through rubber rollersfor some similar wipingdevice to remove the-excess oil.` Y

A After the required reduction -has been accmnplished, however., and-the. rolled piece f trimmed and cut apart into the. regenerated platesM-l and M-Q, I remove the residual oily film with a solvent beforereturning the plates to the several cells, so that electi'olytic actioncan take place uniinpaired. A pickling step may be resorted to ifdesired, though I have not usually found this requi-4 site. The trimfrom successive regeneration steps, I meltl in a small furnace and castinto the supplementary anodes M-'3.

While in a specific example I have described my process in connectionwith certain definite electrolytic steps, I desire it to be understoodciic metals or any specific electrolytic processes. For example, in theiron plating step, instead of vusing the sulphide lof iron anodesdescribed in the patentV application referred to, I may use anelectrolytic step involving the use of insoluble -anodes and theconsequent depletion of the metal content of' the electrolyte, renewinginy electrolyte in a leaching step'. I may thus that the inventionis notlimited toany spe;

produce articles of any metal capable of heilig l deposited on'anothermetal from an electrolyte, and I may use as my start-ing blank any metalcapable of being electrolytically stripped in an electrolyticdifferential solution step andredepyosited in the same step A upon acathode. ,4

Furthern'lor'e, While I have described my process as involving the useof sheetsand as being a sheet-forn'iing process, it isnevere` thelessapplicable to the formation of other caused to flow through it. Theaction of -anelectric current would deposit a tube of the metal M Withinthe blank N tothe required thickness. In the stripping cell D both thecathode and anode would preferably rotate things besides sheets as, forexample, in the and the metal M would be deposited upon the outsideof'the blank M-2.I The resultant composite cathode M--lf-M-Q would be adouble-thickness tube which with suitable intervening annealin'gs,lwould be passed l.

through a tube-drawing die, its length doubled and its Walldiameterhalved, Whereupon it would be cut 4apart into lregeneratedtubes-M-1 and M45-2.' The trim or wastage in the tube-drawing step Wouldbe compen- 'l sated for in 'the same fashion through theV use ofsul'iplem'entary a-nodes M-3- and a supplementary source ofl current.

Having thus described my invention what I claim as new and desire tosecure by Letters Patent is: l

1. A process for articles which consists in providing a. cathode shapedlike the article, but of another metal, plat-ing it on one 'face withthe desired metal and then stripping the cathode metal from the platedbody in an electrolytie cell in which a like cathode is used and uponwhich the stripped metal is plated.

2. A process for forming electrolytic metal t artic-leswhich-consists inproviding a cathode shaped like the article, but of another-metal,plating it-on one. face vwiththe desired metal and then stripping thecathode metal from the plated body in an electrolytic cell in formingelectroly'ticmetal which a like cathode is used and lupon which thestripped metal is plated, and then reducing the thickness of the lastnoted cathode to v provide a new -set of cathodes for both steps of theprocess' 3'. A process for forming electrolytic metal articles whichconsists in providing a cathode shapedlike the article, but of anothermetal, plating' it on oneface with'the desired metal and then stripping;the cathode metal from the plated body in an electrolytic cell in whicha like cathodeis used and upon which the stripped metal is plated, andthen reducing the thickness of the last noted cathode to provide a newset of cathodes for both steps ofthe process, said cathodcs being in theform of flat plates.

4. A process for forming electrolyti'c-nietal articles which consists inprovidingf a cathode shaped like the article, but of another metal7plating it on one face with the desired nietal and then stripping thecathode inetal from the plated body 1n an electrolytic cell in which alike cathode is used and upon which the stripped metal is plated, andthen reducing the thickness ofthe last noted cathode to provide a newset of cathodes for bothsteps of the process, there being additionalcathode metal used as anodic material in-said stripping cell, so as toplate the cathode therein -up to sufficient thickness to allow for scrapin the step of reduction of thickness.

5. A, process for forming electrolyt-ic iron `vided and onto which thestripped copper is plated.

, 6. A process for forming electrolytic iron articles which consists inproviding a. copper cathode shaped like the desired article, plating' itwith iron on one face, and thenstripping the copper from the iron in anelec-trolyt-ic cell in which a copper cathode is provided and onto whichythe stripped copper is placed, then rolling the newly plated cathode toextend its length thus providing new cathodes for a. `further series oflike steps.

\ GIBSON YUNGBLUT.

